CVE-2026-25536

EUVD-2026-5335
MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. This issue has been patched in version 1.26.0.
Race Condition
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.1 HIGH
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
GitHub_MCNA
7.1 HIGH
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 1%
Common Weakness Enumeration
References
https://github.com/modelcontextprotocol/typescript-sdk/issues/204
https://github.com/modelcontextprotocol/typescript-sdk/issues/243
https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7